Sewing machine control system



Filed Oct. 5, 1964 fsf m m T 5 w W m 1..) .M47 m W MJ Y B 0 a! e f 6 m VM y w w United States Patent O 3,298,341 SEWING MACHINE CONTROL SYSTEMGeorge Bonis, Tampa, Fla., assignor to Sunstates Sportswear, Inc.,Tampa, Fla., a corporation of Florida Filed Oct. 5, 1964, Ser. No.401,411 6 Claims. (Cl. 112-219) This invention relates to a sewingmachine control system which operates to insure proper operation of asewing machine without jamming and which is safe and reliable inoperation while being comparatively simple and readily constructed.

This invention was evolved with the general object of providing asimple, reliable and foolproof system for automatic operation 'of asewing machine Without jamups and down-time encountered with prior artmachines. In such machines, jam-ups have often resulted due toactivation of drive means for the needle operating mechanism while thepressure foot is in a released position, the pressurefoot being providedfor holding fabrics while sewing. In addition -to annoyances to theoperators, such jam-ups have been the cause of a large amount ofdown-time and have been quite expensive in factory-type operations.

According to this invention, an operators control is connected to drivemeans for a needle-operating mechanism and to a pressure f-oot foractivating the drive means after operating the pressu-re foot to aholding position and for operating the pressure foot to a releasedposition after deactivation of the drive means. With this arrangement,the pressure foot is down in its fabric-engaging position when theneedle is operated, to prevent jam-ups which might otherwise occur.

According to a specific feature of the invention, the pressure foot isoperated to its holding position at an intermediate position of theoperators control, between a normal position and an operating positionthereof, and the pressure foot is operated to its released position withmovement of the control from the intermediate position toward the normalposition, while the drive means for the needle-operating mechanism isactivated in response to movement of the control to its operatingposition and is deactivated in response to `movement of the control fromthe operating position toward the intermediate position. Thus thedesired sequence of operation is obtained directly in response tomovement of the operators control.

Important features of the invention relate to the provision of meanswhereby movement of the pressure foot to its holding position ispositively required before activation of the drive means can take place,and in the provision of means whereby deactivation of the drive means ispositively required before movement of the pressure foot to its releasedposition can take place. Preferably, a highly reliable fluid-operatedsystem is provided for providing such positive safeguards againstjamming of the sewing machine. In particular, a normally closed valvewhich is opened in response to movement of the pressure foot to itsholding position is connected in series with another normally closedvalve which is opened in response to movement vof the operators controlto its operating position, to supply uid to a fluid-operated means foractivating the drive means for the needle-operating mechanism. Inaddition, a normally open valve which is closed in response toactivation of the drive means is connected in series with anothernormally open valve which is closed in response to movement of theoperators control to an intermediate position, for cutting off thesupply of uid to fluid-operated means which operates the pressure footto its released position. Preferably, and in accordance with a furtherspecific feature, spring means are provided for urging the pressure footto its fabric holding position, and additional spring means ice areprovided for urging the drive means to its deactivated position.

This invention contemplates other objects, features and advantages whichwill become more fully apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings which illustrate apreferred embodiment and in which:

FIGURE 1 is a diagrammatic view illustrating a sewing machine controlsystem constructed according to the principles of this invention, theelements of the system being illustrated with an operators control in anormal condition;

FIGURE 2 is a view like FIGURE l, but with the elements being ilustratedwith the operators control in an intermediate position; and

FIGURE 3 is another view like FIGURE 1, but with the elementsillustrated with the operators control in an operating position.

Referring to the drawings, reference numeral 10 generally designates asewing machine control system constructed according to the principles ofthe invention. The system is utilized in conjunction with theconventional comprises a needle 11 carried by a holder 12 which isreciprocably driven by a sewing machine mechanism 13 which may includeother conventional elements.

Fabric to be sewed is held against a support 15 by a pressure foot 16.

Drive means are provided fo-r the mechanism 13 comprising a motor 18which is mechanically coupled to a shaft 19, as diagrammaticallyillustrated by dotted line 20, with a clutch element 21 being carried bythe shaft 19-for engagement with a second clutch element 22 on a shaft23 mechanically coupled to the sewing machine mechanism 13, asdiagrammatically indicated by the dotted line 24.

For controlling engagement of the clutch elements 21 and 22, the shaft19 is axially movable by means of a conventional shifting dog 25connected to a lever 26 pivotal on a shaft 27. The end of lever 26 isconnected to the upper end of a connecting rod 28 connected at its lowerend -to a piston 29 movable in a cylinder 30. The piston is urgedupwardly by a spring 31 to disengage the clutch elements 21 and 22, butmay be moved downwardly by admission of compressed airor other uid intothe upper end of the cylinder 30, to effect engagement of the clutchelements 21 and 22, and thereby activate the drive means for the sewingmachine mechanism 13.

To control movement of the pressure foot 16, it is connected to one endof a lever 33` pivoted at an intermediate point on a shaft 34 and havingits other end connected to the upper end of a connecting rod 3S which isconnected at its lower end to a piston 36 movable in a cylinder 37. Acompression spring 38 is disposed within the cylinder 37 to urge thepiston 36 upwardly and to move the pressure foot downwardly into afabric-holding position. However, the pisto-n 36 is normally urgeddownwardly to a position as illustrated in FIGURE 1, by admission ofcompressed air or other fluid to the upper end of the cylinder 37.

For control of the system, an operators control is provided in the formof a foot pedal 39 pivotal on a shaft 40 supported from a fixed support41, with the foot pedal 39 being urged upwardly by the compressionspring 42. The foot pedal 39 controls a cam lobe 44 operative to engagebuttons 45 and 46 of a normally open valve 47 and a normally closedvalve 48.

In general, when the foot pedal 39 is in a normal position asillustrated in FIGURE 1, compressed air is supplied through the valve 47to the cylinder 37, to lower the piston 36 and raise the pressure foot16, while with the valve 48 being closed, no compressed air is suppliedto the cylinder 30, and the piston 29 is moved upwardly by thecompression spring 31 to disengage the clutch elements 21 and 22. At anintermediate position of the foot pedal 39, as illustrated in FIGURE 2,the normally open valve 47 is closed to cut off the supply ofcornpressed air to the upper end of the cylinder 37, and to allow thepiston 36 to be raised by the compression spring 38, so as to move thepressure foot 16 downwardly to a fabric-holding position. The valve 48,however, remains closed so that the clutch elements 21 and 22 aredisengaged.

When the foot pedal 39 is moved fully downwardly to an operatingposition as illustrated in FIGURE 3, the cam lobe 44 is engaged withboth of the buttons 45 and 46 to 4close the normally open valve 47 andto open the Ynormally closed valve 48, so that the pressure foot 16 isheld in its fabric-holding position, while compressed air is suppliedthrough the valve 4S to the upper end of the cylinder 30 to move thepiston 29 downwardly and to engage the clutch elements 21 and 22.

For supplying compressed air to the valve 47, it is connected through aconduit 49 to a T-fitting 50 connected to the outlet of a pressureregulator valve 51 having an inlet connected through a conduit 52 to asuitable compressed air source.

In accordance with an important feature of the invention, the valve 47is connected through a conduit 53 to a normally open valve 54 connectedthrough a conduit 55 to the upper end of thecylinder 37. The normallyopen valve 54 has an actuating button 55 engageable by a cam lobe 56 onthe connecting rod 28, when the piston 29 is moved downwardly. With thisarrangement, the valve 54 is opened only when the piston 29 is elevated,and the pressure foot 16 can be moved upwardly to a released .positiononly when the clutch elements 21 and 22 are disengaged.

According to another important feature of the invention, theV valve 48is connected through a conduit 58 to the upper end of the cylinder 30and is connected through a conduit 59 to a normally closed valve 60connected through a conduit 61 to the T-fitting 50. 'I'he normallyclosed valve 60 has an actuating button 62 engageable by a cam lobe 63on the connecting rod 35 when the piston 36 is elevated. The valve 60 isthus opened and compressed air can be supplied to the cylinder 30 toengage the clutch elements 21 and 22 only when the piston 36 has beenelevated to move the pressure foot 16 downwardly to its fabric-holdingposition.

It will be noted that should the compressed air fail in any lineyleading to the cylinder 30, the only thing that can happen is that theclutch elements 21 and 22 would disengage and the sewing machinemechanism would be stopped. If for any reason the air should fail in anyline leading t-o the cylinder 37, the only thing that can happen is thatthe pressure foot 16 would remain down since pressure is required toraise it. In no case can the needlebe operated without the pressure footbeing down, and jam-ups and downtime are avoided.

This invention thus provides a sewing machine control system whichoperates to insure proper operation of a sewing machine without jammingand which is safe and reliable in operation while being comparativelysimple and readily constructed.

It will be understood that modifications and variations may be effectedwithout departing from the spirit and scope of the novel -concepts ofthis invention.

I claim as my invention:

1. In a sewing machine including a needle, a mechanism for operatingsaid needle, drive means for said mechanism, and a pressure footoperable from a released position to a normally resiliently biasedfabric-holding position, an operators control movable from a normalposition through an intermediate position to an operating position, rstiiuid means connected to said control and to said pressure footregulating the movement of said pressure foot to said fabric-holdingposition in response to movement of said control from said normalposition to said intermediate position and for operating said pressurefoot to said released position in response to movement of said controlfrom said intermediate position toward said normal position, secondfluid means connected to said operators control and said drive meansregulating the movement of said drive means in response to movement ofsaid control to said operating position from a normally resilientlybiased non-operating position and for deactivating said drive means inresponse to movement of said control from said operating position towardsaid intermediate position and fluid interlock means separate from saidfirst and second fluid means connected to said second iiuid meansresponsive to activation of said pressure foot regulating operation ofthe drive means whereby when said pressure foot is in the releasedposition the drive means is held in an inoperative position.

, 2. In a sewing machine including a needle, a mechanism for operatingsaid needle, drive means for said mechanism, and a pressure footoperable from a released position to a fabric-holding position, anoperators control movable from a normal position through an intermediateposition to an operating position, resilient means urging said pressurefoot toward said fabric-holding position, first fluid means connected tosaid operators control and to said pressure foot for operating saidpressure foot to said fabric-holding position in response to movement ofsaid control from said normal position to said intermediate position andfor operating sai-d pressure foot to said released position in responseto movement of said control from said intermediate position toward saidnormal position, second fiuid means connected to lsaid operators controland said drive means for activating said drive means in response tomovement of said control to said operating position and for deactivatingsaid drive means in response to movement of said control from saidoperating position towar-d said intermediate position, first fluidinterlock means responsive to activation of said drive means acting onthe means connected to said control and the pressure foot preventingoperation of said pressure foot to said released position while saiddrive means is activated and second fluid interlock means responsive toactivation of said pressure foot preventing operation of the drive meanswhen said pressure foot is in the released position.

3. In a control system for a sewing machine including a needle, amechanism for operating said needle, drive means for said mechanism, apressure foot operable from a released position to a fabric-holdingposition and an operators control movable from a normal position throughan intermediate position to an operating position, said control systemincluding first spring means for operating said pressure foot to saidfabric-holding position, second spring means operated in conjunctionwith said drive means for urging said drive means to a deactivatedcondition, first fluid-operated means for operating against said firstspring means to operate said pressure foot to said released position,second Huid-operated means operating against said second spring meansfor activating said drive means, a source of fluid under pressure, anormally open valve connecting said source of fluid under pressure tosaid first uid-operated means, a normally closed valve connected betweensaid source of fluid under pressure and said second fluid-operatedmeans, means coupled to said operators control and operable in responseto movement thereof to said intermediate position for closing saidnormally open valve and operable in response to movement of said controlto said operating position for opening said normally closed valve asecond normally closed valve in series with said first normally closedvalve between said valve and said source of pressure arranged to beopened upon movement of said pressure foot to said fabric holdingposition whereby fiuid from said source of pressure may reach said firstnormally closed valve, and a second normally open valve between saidfirst normally open valve and said first fiuid operated means arrangedto be closed in response to activation of said drive means whereby tohold said first fluid operated means against movement while said drivemeans is activated.

4. In a control system for a sewing machine including a needle, amechanism for operating said needle, drive means for said mechanism, apressure foot operable from a released position to a fabric-holdingposition, and an operators control movable from a normal positionthrough an intermediate position to an operating position, said controlsystem including first spring means for operating said pressure foot tosaid fabric-holding position, second spring means operated inconjunction with said drive means for urging said drive means to adeactivated condition, first Huid-operated means for operating againstsaid first spring means to operate said pressure foot to said releasedposition, second fluid-operated means operating against said secondspring means for activating said drive means, a source of fluid underpressure, a normally open valve connecting said source of fluid underpressure to said first fluid-operated means, a normally closed valveconnected between said source of fluid -under pressure and said secondfluid-operated means, means coupled to said operators control andoperable in response to movement of said control to said operatingposition for closing said normally open valve and operable in responseto movement of said control to said operating position for opening saidnormally closed valve, and a second normally closed valve connected inseries with said first normally closed valve between said valve and saidsource of pressure and arranged to be opened upon movement of saidpressure foot to said fabric-holding position whereby fiuid from saidsource of pressure may reach said first normally closed valve.

5. In a control system for a sewing machine including a needle, amechanism for operating said needle, drive means for said mechanism, apressure foot operable from a released position to a fabric-holdingposition and an operators control movable from a normal position throughan intermediate position to an operating position, said control systemincluding first means for operating said pressure foot to saidfabric-holding position, second means operated in conjunction with saiddrive means for urging said drive means to a deactivated condition,first fluidoperated means for operating against said first means tooperate said pressure foot to said released position, secondfluid-operated means operating against said second means for activatingsaid drive means, a source of fluid under pressure, a normally openvalve connecting said source of fluid under pressure to said firstfluid-operated means, a normally closed valve connected between saidsource of fluid under pressure and said second fluid-openated means,means coupled to said operators control and operable in response tomovement thereof to said intermediate position for closing said normallyopen valve and operable in response to movement of said control to saidoperating position for opening said normally closed valve, a secondnormally closed valve in series with said first normally closed valvebetween said valve and said source of pressure arranged to -be openedupon movement of said pressure foot to said fabric-holding positionwhereby fluid from said source of pressure may reach said first normallyclosed valve, and a second normally open valve lbetween said firstassembly open valve and said first fluid operated rneans arranged to beclosed in responsey to activation of said drive means whereby to holdsaid first fluid operated means against movement while said drive meansis activated.

6. In a control system for a sewing machine including a needle, amechanism for operating said needle, drive means for said mechanism, apressure foot operable from a released position to a fabric-holdingposition and an operators control movable from a normal position throughan intermediate position to an operating position, said control systemincluding first means for operating said pressure foot to saidfabric-holding position, second means operated in conjunction with saiddrive means for urging said drive means to a deactivated condition,first fluid-operated means for operating -against said first means tooperate said pressure foot to said released position, secondfluid-operated means operating against said second means for activatingsaid drive means, a source of fluid under pressure, a normally openvalve connecting said source of fluid under pressure to said firstfiuid-operated means, a normally closed valve connected between saidsource of fluid under pressure and said second fluidoperated means,means coupled to said operatorscontrol and operable in response tomovement thereof to said intermediate position for closing said normallyopen valve and operable in response to movement of said control to saidoperating position for opening said normally closed valve, and a secondnormally closed valve connected in series with said first normallyclosed valve between said valve and said source of pressure :andarranged to be opened upon movement of said pressure foot to saidfabric-holding position whereby fluid from said source of pressure mayreach said first normally closed valve.

References Cited by the Examiner UNITED STATES PATENTS 2,385,768 10/1945Althaus 112-219 2,540,730 2/1951 Hayes i12-67 2,722,184 11/1955 sweet112-219X 2,764,112 9/1956 Happe 112-219 X 3,245,369 4/1966 Myska 112-219X JORDAN FRANKLIN, Primary Examiner.

H. H. HUNTER, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,298,341 January 17, 1967 George Bonis It is hereby certified that errorappears in the above numbered patent requiring correction and that thesaid Letters Patent should read as corrected below.

Column 2, line 14, for "lustrated" re-ad illustrated line 22,4 after"conventional" insert sewingl machine which as diagrammatcallyillustrated column 5, line 27, after "movement" strike out "of saidcontrol to said operation" and insert instead thereof to saidintermediate Signed and sealed this 7th day of November 1967.

(SEAL) Attest:

EDWARD J. BRENNER Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer

1. IN A SEWING MACHINE INCLUDING A NEEDLE, A MECHANSIM FOR OPERATINGSAID NEEDLE, DRIVE MEANS FOR SAID MECHANISM, AND A PRESSURE FOOTOPERABLE FROM A RELEASED POSITION TO A NORMALLY RESILIENTLY BIASEDFABRIC-HOLDING POSITION, AN OPERATOR''S CONTROL MOVABLE FROM A NORMALPOSITION THROUGH AN INTERMEDIATE POSITION TO AN OPERATING POSITION,FIRST FLUID MEANS CONNECTED TO SAID CONTROL AND TO SAID PRESSURE FOOTREGULATING THE MOVEMENT OF SAID PRESSURE FOOT TO SAID FABRIC-HOLDINGPOSITION IN RESPONSE TO MOVEMENT OF SAID CONTROL FROM SAID NORMALPOSITION TO SAID INTERMEDIATE POSITION AND FOR OPERATING SAID PRESSUREFOOT TO SAID RELEASED POSITION IN RESPONSE TO MOVEMENT OF SAID CONTROLFROM SAID INTERMEDIATE POSITION TOWARD SAID NORMAL POSITION, SECONDFLUID MENS CONNECTED TO SAID OPERATOR''S CONTROL AND SAID DRIVE MEANSREGULATING THE MOVEMENT OF SAID DRIVE MEANS IN RESPONSE TO MOVEMENT OFSAID CONTROL TO SAID OPERATING POSITION FROM A NORMALLY RESILIENTLYBIASED NON-OPERATING POSITION AND FOR DEACTIVATING SAID DRIVE MEANS INRESPONSE TO MOVEMENT OF SAID CONTROL FROM SAID OPERATING POSITION TOWARDSAID INTERMEDIATE POSITION AND FLUID INTERLOCK MEANS SEPARATE FROM SAIDFIRST AND SECOND FLUID MEANS CONNECTED TO SAID SECOND FLUID MEANSRESPONSIVE TO ACTIVATION OF SAID PRESSURE FOOT REGULATING OPERATION OFTHE DRIVE MEANS WHEREBY WHEN SAID PRESSURE FOOT IS IN THE RELEASEDPOSITION THE DRIVE MEANS IS HELD IN AN INOPERATIVE POSITION.